Since averaging 3.0 runs and hitting .143 with runners in scoring position while losing four of five, the Nationals -- who rank in the bottom third of the majors in both categories -- have scored 7.6 per game and batted .340 in those situations during their winning streak.

Harper has a .393 average with five doubles over a seven-game hitting streak, while Moore is 11 for 21 in his last five.

Now the Nationals have a chance to move two games above .500 for the first time since July 11. They still trail Cincinnati by 8 1/2 games for the NL's second wild card, but hope to keep chipping away behind Haren (8-11, 4.64 ERA).

After losing a career-worst eight straight while posting a 6.18 ERA, Haren has gone 4-0 with a 1.36 ERA in his last five starts. Opponents are hitting just .164 against him in this stretch.

The right-hander gave Johnson another solid outing Tuesday when he gave up one run and five hits over six innings in a 4-2 win at Wrigley Field.

Haren has been particularly good on the road of late, going 2-0 with an 0.47 ERA with 19 strikeouts over 19 innings in his last three starts. He's also been outstanding in Kansas City with a 4-0 record and 1.99 ERA in six career starts.

Billy Butler is hitting .333 lifetime against Haren and has a .364 average over his last 20 games overall.

Since 17-3 push put them a season-best eight games over .500 on Aug. 12, the Royals (64-64) have dropped 10 of 12 to fall back to the break-even mark.

"It's frustrating," Gordon said. "I don't like losing streaks and I don't like losing streaks after we've been playing so well."

Kansas City, eight games out of the final AL wild-card spot, looks to snap a seven-game losing streak by sending Ervin Santana (8-7, 3.13) to the mound.

The right-hander yielded two runs -- one earned -- and four hits in six frames in a 2-0 defeat to the White Sox on Tuesday. That's his only loss while winning three and posting a 2.45 over his last seven starts.

Santana hasn't faced the Nationals since he was with the Los Angeles Angels in 2011, but has posted a 3.10 ERA with 20 strikeouts over 20 1/3 innings in three lifetime starts against them.

Washington's Jayson Werth hopes to play after sitting out Saturday with an infection between the toes of his right foot.

Regular Season Series

Research Notes

Dan Haren has registered five straight quality starts, allowing only five runs over 33 innings in that span. His slider has been much improved, limiting opponents to a .217 average (10-of-46) during the stretch, compared with a .360 average prior. His opponent on Sunday, the Royals, have the third-worst average against sliders this season (.211) and the worst well-hit average (.084).

Most Leadoff HR in Royals History

J.J. Hardy has homered as well now. His 45 HR as a SS are the most in MLB over the last 2 seasons. After Desmond's 44, no other player has more than 30 (Troy Tulowitzki).
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Ian Desmond: solo HR in 4th inning (44 over last 2 seasons, 2nd-most by SS - J.J. Hardy has 45).

From Elias: Bryce Harper hit his 40th career HR today, the third most by any player before his 21st birthday.